How to make a chevron border?

Question

css

Good afternoon, I have the following block:

It is made using a shape with absolute positioning. The problem is that when the resolution is reduced, this arrow remains in place and disrupts the overall view. I tried to do it with help. border, but it didn't work for me.
In general, I need such a solution using Border. Who will tell you where to look or can give a ready-made code?